In recent years, since a virtualization of computing resources is developed and virtual computers can be deployed in a network on-demand, an SDN (Software Defined Networking) has attracted attention.
The SDN is a technology available to set or change a network on demand with software. Thus, applying the SDN to a network in which plural flow switches are managed and controlled by a single controller has been studied.
An open flow (OF) protocol is one of promising candidates of a communication protocol available to implement the SDN in such a network. The controller is possible to manage and control each flow switch by communicating with each flow switch using the OF protocol.
A controller that supports the OF protocol may be referred to as an OF controller (OFC) and a flow switch that supports the OF protocol may be referred to as an OF switch (or OpenFlow SW).